Vaporization device and vaporization system

ABSTRACT

In order to make it possible to accurately detect the liquid level of a liquid material in a container, a vaporization device is adapted to include: a container 10 that contains a liquid material X; a heater 30 that heats the liquid material X in the container 10; and a liquid level sensor 20 that detects the liquid level of the liquid material in the container 10, in which when viewing the inside of the container 10 from above, a vaporization region S1 in which the liquid material X is vaporized, and a liquid level stable region S2 different from the vaporization region S1 are configured to be formed, and the liquid level sensor 20 detects the liquid level of the liquid material X in the liquid level stable region S2.

TECHNICAL FIELD

The present invention relates to a vaporization device that vaporizes aliquid material, and to a vaporization system using the vaporizationdevice.

BACKGROUND ART

As this sort of vaporization device, as disclosed in Patent Literature1, there is one including: a container into which a liquid material isintroduced; and a heater for heating the liquid material in thecontainer and configured to heat the liquid material to vaporize it andlead the resulting gas out of the container to introduce it into variousequipment.

This vaporization device further includes a liquid level sensor insertedinto the container in order to make it possible to check the remainingamount of the liquid material in the container.

However, bubbling due to vaporizing the liquid material occurs in thecontainer, and therefore there is a problem of being unable toaccurately detect a liquid level for reasons such as fluctuation of theliquid level and attachment of the liquid material scattered from aliquid surface to the liquid level sensor. Such a problem becomes morenoticeable as a vaporization device is downsized.

CITATION LIST Patent Literature

Patent Literature 1

Japanese Unexamined Patent Publication JP-A-07-194961

SUMMARY OF INVENTION Technical Problem

Therefore, the present invention has been made in order to solve theabove-described problem, and the main object thereof is to provide avaporization device capable of accurately detecting the liquid level ofa liquid material in a container.

Solution to Problem

That is, the vaporization device of the present invention is oneincluding: a container that contains a liquid material; a heater thatheats the liquid material in the container; and a liquid level sensorthat detects the liquid level of the liquid material in the container,in which when viewing the inside of the container from above, avaporization region in which the liquid material is vaporized, and aliquid level stable region are formed, and the liquid level sensordetects the liquid level of the liquid material in the liquid levelstable region.

In the vaporization device configured as described, when viewing theinside of the container from above, the vaporization region and theliquid level stable region are formed, and the liquid level sensordetects the liquid level in the liquid level stable region, thus makingit possible to accurately detect the liquid level of the liquid materialin the container.

In addition, the liquid level stable region here is not limited to aregion in which the liquid level does not fluctuate at all, and to theextent that detection accuracy by the liquid level sensor can beimproved more than before, the liquid level may fluctuate.

As a more specific embodiment, a configuration in which the heater isprovided to part of a side wall of the container or to the vicinity ofit can be cited.

In such a configuration, a side where the heater is arranged in thecontainer can be actively heated to form the vaporization region on theheater side and also form the liquid level stable region on a sideopposite to the heater. As a result, fluctuation occurring on a liquidsurface in the vaporization region can be reduced until reaching theliquid level stable region, and the liquid material scattered from theliquid surface in the vaporization region can be prevented from reachingthe liquid level sensor, thus making it possible to accurately detectthe liquid level of the liquid material.

It is preferable to further include a separation member that separatesbetween the vaporization region and the liquid level stable region so asto enable the liquid material to be circulated between these regions.

In such a configuration, the separation member can surely prevent theliquid level in the vaporization region from fluctuating and the liquidmaterial scattered from the liquid surface in the vaporization regionfrom reaching the liquid level stable region.

In order to keep the liquid level at the same height between thevaporization region and the liquid level stable region, it is preferablethat the separation member separates between the vaporization region andthe liquid level stable region so as to enable material gas resultingfrom vaporization of the liquid material to be circulated between theseregions.

As a specific embodiment for forming the vaporization region and theliquid level stable region in the container, one configured so that acalorific value given per unit volume per unit time is lower in theliquid level stable region than in the vaporization region can be cited.

Meanwhile, if the material gas resulting from vaporization of the liquidmaterial is condensed and liquefied in the container, the liquidmaterial may be led out of the container together with the material gasto make it impossible to accurately control, for example, the flow rateof the material gas, or the like.

Accordingly, in order to suppress the material gas from being liquefied,it is preferable to include a heater that is provided in an upper partof the container and heats material gas resulting from vaporization ofthe liquid material.

Even if the material gas is liquefied in the container, in order toprevent the liquid material resulting from the liquefaction from beingled out of the container together with the material gas, it ispreferable that a lead-out port for leading material gas resulting fromvaporization of the liquid material out of the container is provided ona vaporization region side of the container.

In a configuration in which the liquid material is introduced into thevaporization region, the introduced liquid material may be vaporized atonce to rapidly raise the pressure inside the container, possibly makingit impossible to accurately control, for example, the flow rate of thematerial gas.

Accordingly, in order to avoid a rapid pressure rise in the container,it is preferable that an introduction port for introducing the liquidmaterial into the container is formed on a liquid level stable regionside of the container.

Also, the vaporization system according to the present invention is oneincluding: the above-described vaporization device; a liquid materialsupply device that supplies the liquid material to the vaporizationdevice; and a control device that controls the supply amount of theliquid material on the basis of a detection signal of the liquid levelsensor.

In such a vaporization system, the liquid level sensor can accuratelydetect the liquid level of the liquid material, thus making it possibleto improve control of the supply amount of the liquid material by thecontrol device.

Advantageous Effects of Invention

According to the present invention configured as described, even in thecase of the device of a small size, the liquid surface of the liquidmaterial in the container can be accurately detected.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram schematically illustrating the configuration of avaporization system in one embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating the configuration of avaporization device in the same embodiment.

FIG. 3 is a diagram when viewing the vaporization device in the sameembodiment from a level direction of a liquid level.

FIG. 4 is a diagram when viewing a vaporization device in anotherembodiment from a level direction of a liquid level.

FIG. 5 is a diagram schematically illustrating the configuration of avaporization device in another embodiment.

FIG. 6 is a diagram schematically illustrating the configuration of avaporization device in another embodiment.

FIG. 7 is a diagram schematically illustrating the configuration of avaporization device in another embodiment.

LIST OF REFERENCE CHARACTERS

100 Vaporization device

X Liquid material

10 Container

20 Liquid level sensor

30 Heater

P1 Introduction port

P2 Lead-out port

11 Side wall

S1 Vaporization region

S2 Liquid level stable region

40 Separation member

DESCRIPTION OF EMBODIMENTS

In the following, one embodiment of the vaporization device according tothe present invention will be described with reference to drawings.

A vaporization device 100 of the present embodiment is one constitutingpart of a vaporization system Z used in a manufacturing process of, forexample, semiconductors or the like, and as illustrated in FIG. 1, isintroduced with a liquid material X from a liquid material supply device200 through an introduction path L1 and vaporizes the liquid material Xto produce material gas. The material gas produced by the vaporizationdevice 100 is sent to target equipment through a lead-out path L2 asillustrated in FIG. 1.

The introduction path L1 and the lead-out path L2 are respectivelyprovided with on-off valves V1, V2, and adapted to be switchable to anyone, for example, whether introducing the liquid material X into thevaporization device 100 or leading the material gas out of thevaporization device 100 by opening/closing these on-off valves V1, V2appropriately depending on circumstances. In addition, it is alsopossible to open both the on-off valves V1, V2, and close both.

Specifically, the supply amount of the liquid material X is adapted tobe controllable in such a manner that the below-described liquid levelsensor 20 detects the liquid level of the liquid material X in thevaporization device 100 and on the basis of the resulting detectionsignal, an unillustrated control device adjusts the opening level of theon-off valve V1 provided in the introduction path L1.

Also, the lead-out path L2 is provided with a flow rate controller MFCsuch as a differential pressure type or thermal type mass flowcontroller, and adapted to be able to control the flow rate of thematerial gas flowing through the lead-out path L2 to, for example, apreset target flow rate. In addition, a control valve constituting theflow rate controller MFC can be provided with a function as theabove-described on-off valve V2, and in such a case, the on-off valve V2is not necessarily required to be provided.

As illustrated in FIG. 2, the vaporization device 100 of the presentembodiment includes: a container 10 that contains the liquid material X;the liquid level sensor 20 that detects the liquid level of the liquidmaterial X in the container 10; and a heater 30 that heats the liquidmaterial X in the container 10.

The container 10 is one whose inside is formed as a vaporization chamberS for vaporizing the liquid material X and that is, for example, of acasing shape. The container 10 here is one of a vertically-longvertically-mounted type, and formed with an introduction port P1connected with the above-described introduction path L1 and a lead-outport P2 connected with the above-described lead-out path L2.

The introduction port P1 is positioned in the lower part of thecontainer 10, and specifically, formed in the lower end part of a sidewall 11 of the container 10. In addition, the introduction port P1 maybe formed in the bottom wall 12 of the container 10 or may be providedin the upper part of the container 10.

The lead-out port P2 is positioned in the upper part of the container10, and specifically, formed in the upper end part of a side wall 11 ofthe container 10. In addition, the lead-out port P2 may be formed in theupper wall 13 of the container 10.

The liquid level sensor 20 can use various types, such as a contact-typethat detects the liquid level with a sensor part (not illustrated) incontact with the liquid material X, a noncontact-type that detects theliquid level with a sensor part not in contact with the liquid materialX, a type having a movable part like a float type, and a type not havinga movable part like an electrode type. Note that in the case of having amovable part, particles may be produced in the container 10, andtherefore the liquid level sensor 2 not having a movable part is usedhere.

Specifically, the liquid level sensor 20 is a contact-type one insertedinto the container 10 through an insertion hole provided in the upperwall 13 of the container 10, and configured to include a resistancetemperature detector (not illustrated) such as a thermistor and to beable to detect the liquid level using the difference in heat dissipationfactor between a liquid phase and a gas phase.

The heater 30 can use various types such as ones using a cartridgeheater and a heating wire heater, and is a rubber heater constituted by,for example, silicon and the like. Note that the detailed arrangement ofthe heater 30 will be described below.

Further, as illustrated in FIG. 3, when viewing the inside of thecontainer 10 from above (an arrow R direction in FIG. 2) (i.e., asviewed from a level direction of the liquid level stable in thecontainer 10), the vaporization device 100 of the present embodiment isconfigured to form a vaporization region S1 in which the liquid materialX in the container 10 is vaporized and a liquid level stable region S2in which the liquid level is stable differently from the vaporizationregion S1, and the above-described liquid level sensor 20 is arranged soas to detect the liquid level in the liquid level stable region S2. Inaddition, the vaporization region S1 and the liquid level stable regionS2 are not required to be strictly distinct regions, but thevaporization region S1 and the liquid level stable region S2 maypartially overlap each other in a boundary part in cases such as whenthese regions S1, S2 are continuously formed.

The vaporization region S1 is a region on a side where theabove-described heater 30 is provided in the container 10, and a regionin which the liquid material X is actively heated. The vaporizationregion S1 here is a region in which a calorific value given per unitvolume per unit time is higher than that in the liquid level stableregion S2 and bubbles of various sizes are generated.

On the other hand, the liquid level stable region S2 is a region on aside where the above-described liquid level sensor 20 is provided in thecontainer 10, and a region in which a variation in liquid level issmaller than that in the vaporization region S1. The liquid level stableregion S2 here is a region whose temperature is lower than that in thevaporization region; however, in cases such as when the container 10 isof a small size, the liquid level stable region S2 and the vaporizationregion S1 may become substantially equalized in temperature. Inaddition, the liquid level stable region S2 is not required to be aregion in which the liquid level does not fluctuate at all, and to theextent that the detection accuracy of the liquid level sensor 20 can beimproved more than before, the liquid level may fluctuate, bubbles maybe generated, or the liquid material X may be vaporized.

As illustrated in FIG. 2 and FIG. 3, the vaporization region S1 and theliquid level stable region S2 in the present embodiment are formed byarrangement of the above-described heater 30, and here the vaporizationdevice 10 is further provided with a separation member 40 separatingbetween the vaporization region S1 and the liquid level stable regionS2.

Describing more specifically, the heater 30 is provided to part of theperiphery of the vaporization chamber S without surrounding the whole ofthe vaporization chamber S. In doing so, in the vaporization chamber S,a region that is near to the heater 30 and in which the amount of heattransferred is large serves as the vaporization region S1, and a regionthat is far from the heater 30 and in which the amount of heattransferred is small serves as the liquid level stable region S2.

The heater 30 here is provided to part of the side wall of the container10, and arranged so as to partially heat the liquid material X. Inaddition, the heater 30 is not necessarily required to be provided tothe side wall 11, but may be provided in the vicinity of the side wall11, or may be separated from the side wall 11 to the extent that theliquid material X can be vaporized. That is, the heater 30 may beprovided integrally with the side wall 11, or may be formed as aseparate body from the side wall 11 and provided separately from theside wall 11.

The container 10 in the present embodiment is of a rectangularparallelepiped shape, and as illustrated in FIG. 3, has: a first sidewall 111 and a second side wall 112 which are opposite to each other;and a third side wall 113 and a fourth side wall 114 which areinterposed between them and opposite to each other. In the presentembodiment, the heater 30 is provided to the second side wall 112without being provided to the first side wall 111. It may beappropriately selected whether or not to provide the heater 30 to thethird side wall 113 or to the fourth side wall 114; however, in the caseof providing, without providing at least on the first side wall 111 sideof the third side wall 113 or fourth side wall 114, providing on thesecond side wall 112 side is preferable.

In the present embodiment, as illustrated in FIG. 2, in addition to theabove-described heater 30 (hereinafter also referred to as a firstheater 31), a second heater 32 for heating the material gas resultingfrom vaporization of the liquid material X is provided in the upper partof the container 10, and a third heater 33 for making the vaporizationof the liquid material X highly efficient is provided in the lower partof the container 10.

In addition, the first heater 31, the second heater 32, and the thirdheater 33 may be ones that are respectively separate bodies, or may beones that are partially or wholly integrally formed.

The second heater 32 is one that suppresses the material gas from beingliquefying, and provided at least on the vaporization region S1 side inthe upper wall 13 of the container 10. In addition, the second heater 32may be provided from the vaporization region S1 side to the liquid levelstable region S2 side in the upper wall 13, or may be provided from theupper wall 13 to the upper part of the first side wall 111. Also, thesecond heater 32 is not necessarily required to be provided to the upperwall 13, but may be provided in the vicinity of the upper wall 13, ormay be separated from the upper wall 13 to the extent that the materialgas can be suppressed from liquefying.

The third heater 33 is one that heats the liquid material X, andprovided on the vaporization region S1 side in the bottom wall 12 of thecontainer 10. In addition, the third heater 33 is not necessarilyrequired to be provided to the bottom wall 12, but may be provided inthe vicinity of the bottom wall 12, or may be separated from the bottomwall 12 to the extent that the liquid material X can be heated.

The separation member 40 is one that, as illustrated in FIG. 2 and FIG.3, is interposed between the vaporization region S1 and the liquid levelstable region S2 in the container 10, and makes it possible to circulatethe liquid material X between the vaporization region S1 and the liquidlevel stable region S2, as well as to also here circulate the materialgas between the vaporization region S1 and the liquid level stableregion S2.

Specifically, the separation member 40 is one provided substantiallyparallel to the first side wall 111 and the second side wall 112, andhere, for example, a rectangular-shaped flat plate provided from thethird side wall 113 to the fourth side wall 114. In order to make thevolumes of the vaporization region S1 and the liquid level stable regionS2 substantially equal to each other, the separation member 40 separatesbetween these regions S1, S2. In addition, the shape and arrangement ofthe separation member 40, the volume ratio between the vaporizationregion S1 and the liquid level stable region S2 separated by theseparation member 40, and the like may be appropriately changed.

In the present embodiment, the lower end of the separation member 40 isseparated from the bottom wall 12 to make it possible to circulate theliquid material X through the resulting interval, and also the upper endof the separation member 40 is separated from the upper wall 13 to makeit possible to circulate the material gas through the resultinginterval. In other words, the interval between the lower end of theseparation member 40 and the bottom wall 12 allows a liquid phase in thevaporization region S1 and a liquid phase in the liquid level stableregion S2 to communicate together, and also, the interval between theupper end of the separation member 40 and the upper wall 13 allows a gasphase in the vaporization region S1 and a gas phase in the liquid levelstable region S2 to communicate together. Note that the liquid phasehere refers to a region in which liquid exists, and the gas phase refersto a region in which gas exists.

Here, in the liquid level stable region S2, the above-described liquidlevel sensor 20 is provided, and specifically, arranged so that thelower end of the liquid level sensor 20 is positioned lower than theupper end of the separation member 40. Also, in the liquid level stableregion S2, the above-described introduction port P1 is provided, andhere the introduction port P1 is formed in a position opposite to thefirst heater 31, i.e., in the first side wall 111.

On the other hand, in the vaporization region S1, the above-describedlead-out port P2 is provided, and here formed above the first heater 31in the second side wall 112.

According to the vaporization device 100 according to the presentembodiment configured as described, since the arrangement of the heater30, and the separation member 40 allow the vaporization chamber S to beseparated into the vaporization region S1 and the liquid level stableregion S2, and also the liquid level sensor 20 is configured to detectthe liquid level in the liquid level stable region S2, it can beprevented that the fluctuation of the liquid level due to bubblingoccurring in the vaporization region S1 arrives at the liquid levelstable region S2 and that the liquid material X scattered from theliquid surface in the vaporization region S1 is attached to the liquidlevel sensor 20.

As a result, the liquid level of the liquid material X can be accuratelydetected by the liquid level sensor 20, and on the basis of the detectedliquid level, for example, it becomes possible to accurately control thesupply amount of the liquid material X and accurately grasp theremaining amount of the liquid material X in the container 10. Suchworking effects are more noticeably produced as the vaporization device100 is downsized; however, it goes without saying that even thevaporization device 100 of a large size can obtain the same workingeffects.

Also, since the material gas can pass between the vaporization region S1and the liquid level stable region S2, pressure is substantially thesame between the gas phase in the vaporization region S1 and the gasphase in the liquid level stable region S2, making it possible to makethe liquid level substantially the same between the vaporization regionS1 and the liquid level stable region S2.

Further, since the material gas is heated by the second heater 32, thematerial gas can be suppressed from liquefying. Still further, since thelead-out port P2 is formed in the vaporization region S1, even if thematerial gas liquefies, the liquid material X resulting from theliquefaction can be prevented from being led out of the container 10,and for example, the accuracy of flow rate control by, for example, themass flow controller or the like can be ensured.

In addition, since the introduction port P1 is formed in the liquidlevel stable region S2, the liquid material X introduced into thecontainer 10 through the introduction port P1 can be prevented frombeing vaporized at once, making it possible to prevent a rapid pressurerise in the container 10.

Note that the present invention is not limited to the above-describedembodiment.

For example, in the above-described embodiment, the second side wall 112is provided with the heater 30; however, the heater 30 may be providedon the vaporization region S1 side in the bottom wall 12, i.e., nearerto the first side wall 111 side (in the vicinity of the first side wall111) than the separation member 40 in the bottom wall 12 without beingprovided to the second side wall 112. That is, it may be configured toprovide the third heater 33 without providing the first heater 31 in thefirst embodiment.

Further, the vaporization device 100 only has to be configured to makethe liquid level stable region S2 lower in temperature than thevaporization region S1 even in a configuration in which the entireperiphery of the side walls 11 (i.e., the first side wall 111, secondside wall 112, third side wall 113, and fourth side wall 114) of thecontainer 10 is provided with the heater 30 or the entire bottom wall 12of the container 10 is provided with the heater 30.

Specifically, one in which the heater 30 is configured so as to make aheating capacity for the liquid level stable region S2 lower than aheating capacity for the vaporization region S1, a configuration inwhich the liquid level stable region S2 is provided with a coolingmechanism, or the like can be cited.

Also, the separation member 40 is not required to be provided from thethird side wall 113 to the fourth side wall 114, but as illustrated inFIG. 4, may be attached to, for example, the bottom wall 12 in such away as to be separated from one or both of the third side wall 113 andthe fourth side wall 114.

Further, the separation member 40 in the above-described embodimentseparates between the vaporization region S1 and the liquid level stableregion S2 while making it possible to circulate the material gas betweenthe vaporization region S1 and the liquid level stable region S2;however, for example, if the gas phase in the liquid level stable regionS2 is opened to the atmosphere, or by other means, the material gas maybe unable to be circulated between the vaporization region S1 and theliquid level stable region S2.

Still further, as illustrated in FIG. 4, the introduction port P1 may beformed on the vaporization region S1 side, and for example, may beformed on the vaporization region S1 side in the second side wall 112,third side wall 113, or fourth side wall 114.

In such a configuration, the liquid material X is not directlyintroduced into the liquid level stable region S2, and therefore theliquid level in the liquid level stable region S2 can be suppressed frombeing fluctuated by introduction of the liquid material X.

On the other hand, as illustrated in FIG. 4, the lead-out port P2 may beformed on the liquid level stable region S2 side, and for example, maybe formed in the upper end part of the first side wall 111, or in theupper end part on the liquid level stable region S2 side in the thirdside wall 113 or the fourth side wall 114.

In such a configuration, the lead-out port P2 can be kept away from theliquid surface in the vaporization region S1, and even when the liquidmaterial X is scattered on the liquid surface in the vaporization regionS1, the scattered liquid material X can be suppressed from arriving atthe lead-out port P2.

In addition, as illustrated in FIG. 5, the vaporization device 100 maybe configured to include: a first container 10A inside which avaporization region S1 is formed; and a second container 10B insidewhich a liquid level stable region S2 is formed and that communicateswith the first container 10A, in which the second container 10B isprovided with a liquid level sensor 20.

Describing more specifically, the first container 10A and the secondcontainer 10B are arranged mutually separated via a space S3, and heretubular members provided so that tube axis directions are parallel toeach other.

The first container 10A is such that the outer circumferential partthereof is provided with a heater 30 (a rubber heater or a windingheater) and the upper end part thereof communicates with a lead-out portP2 for leading out material gas.

The second container 10B is such that the inside thereof is insertedwith the liquid level sensor 20 and the lower end part thereofcommunicates with an introduction port Pb for introducing a liquidmaterial X.

The first container 10A and the second container 10B are configured suchthat the upper end parts thereof communicate with each other, while thelower end parts thereof communicate with each other, and a gas phase inthe first container 10A and a gas phase in the second container 10Bcommunicate together, while a liquid phase in the first container 10Aand a liquid phase in the second container 10B communicate together.

In such a configuration, the space S3 interposed between the firstcontainer 10A and the second container 10B functions as the separationmember 40, the same working effects as in the first embodiment can beobtained without providing the separation member 40 separately from therespective containers 10A, 10B.

As still another embodiment, as illustrated in FIG. 6, the separationmember 40 may be tilted with respect to the first side wall 111 and thesecond side wall 112. Specifically, this separation member 40 isprovided below the liquid level sensor 20, and arranged separated fromthe liquid level sensor 20 so that bubbles generated in the vaporizationregion S1 float along the separation member 40. In other words, in thevaporization device 100, a heater 30 is provided on the second side wall112 side of the bottom wall 12, and the separation member 40 is tiltedin such a manner as to gradually rise from the first side wall 111toward the second side wall 112.

Even in such a configuration, as viewed from the level direction of theliquid level, the vaporization region S1 and the liquid level stableregion S2 can be formed in the container 10, thus making it possible forthe liquid level sensor 2 to accurately detect the liquid level in theliquid level stable region S2.

In addition, the vaporization device 100 may be one not including theseparation member 40.

Specifically, as such a vaporization device 100, as illustrated in FIG.7, a configuration in which a container 10 is a horizontally long one ofwhich one end part in its longer direction is provided with a heater 30and the other end part in the longer direction is provided with a liquidlevel sensor 20 can be cited. In such a configuration, in a vaporizationchamber S of the container 10, one end part side in the longer directionis formed as a vaporization region S1, while the other end part side inthe longer direction is formed as a liquid level stable region S2, andthe liquid level sensor 20 is arranged so as to detect a liquid level inthe liquid level stable region S2.

In such a configuration, a liquid material X scattered from a liquidsurface in the vaporization region S1 can be prevented from arriving atthe liquid level sensor 20, making it possible to accurately detect theliquid level of the liquid material X.

Besides, it goes without saying that the present invention is notlimited to the above-described embodiments, but can be variouslymodified without departing from the scope thereof.

INDUSTRIAL APPLICABILITY

According to the present invention, the liquid level of the liquidmaterial in the container can be accurately detected.

1. A vaporization device comprising: a container that contains a liquidmaterial; a heater that heats the liquid material in the container; anda liquid level sensor that detects a liquid level of the liquid materialin the container, wherein when viewing an inside of the container fromabove, a vaporization region in which the liquid material is vaporized,and a liquid level stable region are formed, and the liquid level sensordetects the liquid level of the liquid material in the liquid levelstable region.
 2. The vaporization device according to claim 1, whereinthe heater is provided to a side wall of the container on a vaporizationregion side or to a vicinity of it.
 3. The vaporization device accordingto claim 1, further comprising a separation member that separatesbetween the vaporization region and the liquid level stable region so asto enable the liquid material to be circulated between these regions. 4.The vaporization device according to claim 3, wherein the separationmember separates between the vaporization region and the liquid levelstable region so as to enable material gas resulting from vaporizationof the liquid material to be circulated between these regions.
 5. Thevaporization device according to claim 1, configured so that a calorificvalue given per unit volume per unit time is lower in the liquid levelstable region than in the vaporization region.
 6. The vaporizationdevice according to claim 1, comprising a heater that is provided in anupper part of the container and heats material gas resulting fromvaporization of the liquid material.
 7. The vaporization deviceaccording to claim 1, wherein a lead-out port for leading material gasresulting from vaporization of the liquid material out of the containeris provided on a vaporization region side of the container.
 8. Thevaporization device according to claim 1, wherein an introduction portfor introducing the liquid material into the container is formed on aliquid level stable region side of the container.
 9. A vaporizationsystem comprising: the vaporization device according to claim 1; aliquid material supply device that supplies the liquid material to thevaporization device; and a control device that controls a supply amountof the liquid material on a basis of a detection signal of the liquidlevel sensor.